Study On Palladium Catalyzed Bifunctionalization Of Olefins To Construct Heterocyclic Compounds

The difunctionalization of olefin is an important organic synthesis reaction,which can easily and efficiently synthesize various natural products,drug molecules and bioactive molecules.In this field,palladium-catalyzed olefin difunctionalization can be used to synthesize important heterocyclic compounds by constructing C-C,C-O,C-N bonds,so it is of great significance to develop novel palladium-catalyzed olefin difunctionalization reactions.In this paper,a new strategy to construct heterocyclic compounds by palladium-catalyzed olefin bifunctional reactions is studied.The research work mainly includes three aspects.1.Palladium-catalyzed synthesis of dihydropyrazoles from allyl hydrazone and aryl bromideDihydropyrazole skeleton is widely found in drugs,natural products and organic molecules.In this chapter,a series of dihydropyrazoles containing aryl-substituted dihydropyrazoles were successfully synthesized by using allyl hydrazone and aryl-bromide as substrates,and C-C and C-N bonds were simultaneously constructed in one step of carbamination reaction.This method provides a practical scheme to obtain a variety of dihydropyrazoles containing aryl substitutions with good yield and good functional group tolerance.2.Palladium-catalyzed synthesis of dihydropyrazoles from allyl hydrazone and alyl bromideOn the basis of palladium-catalyzed carbamination of allyl hydrazone to aryl substituted dihydropyrazole,palladium-catalyzed carbamination of allyl hydrazone and alkenyl bromide was realized,and alkenyl substituted dihydropyrazole compounds could be obtained with good yield.This method provides a practical scheme to obtain dihydropyrazoles containing alenyl substitutions with good yield and good functional group tolerance.3.Synthesis of lactam by palladium-catalyzed asymmetric aza-Heck-Sonogashira tandem reaction of O-phenyl isohydroxamic etherA novel palladium-catalyzed aza-Heck-Sonogashira tandem reaction for the synthesis of lactam was developed.In this reaction system,different arylhydroxamic ethers and various arylenes,alkenes,alkylenes,and natural product derived alkyne substrates can be well compatible,and a series of acetylene-substituted lactam compounds can be synthesized with good yield and excellent enantioselectivity.The method is practical and efficient,and provides a new strategy for the synthesis of chiral lactam.